Conventionally, at a manufacturing site, mass production in which similar products are successively input right-orderly to one manufacture line has been a mainstream. Recently, however, the customary of individual products has been increasing, and therefore, manufacturing sites of multi-product small-volume production are increasing.
A product input to a manufacture line is manufactured passing through a plurality of processes while advancing the line. At each process, the line is sometimes branched and different devices are sometimes provided at destinations of the branches. Therefore, it is necessary to select for each product to which branch the product is to be advanced and by which device the product is to be manufactured. Also the residence time period (manufacture time period) differs among different devices. Since, in a manufacture line, the number of factors for determining input timings of products or devices through which the products are to pass is great in this manner, it is not easy to achieve optimization.
It is to be noted that Japanese Laid-open Patent Publication Nos. 2006-260462, 2009-258863, and 2013-513166 and so forth disclose a technology relating to planning of a production plan (production schedule), optimization of manufacturing processing and so forth.